1. Field of the Invention
The present invention relates generally to a press for manufacturing cans. In particular, the press receives a metallic coil strip or sheet (generally aluminum or steel) and includes a plurality of work stations wherein subsequent tooling for forming a can passes through openings in the metallic sheet formed at the first work station when a blank is punched.
2. Description of the Related Art
Drawn and redrawn cans for containing food and the like are well known. Cans of the two-piece variety are becoming more prevalent since they provide better integrity and less potential for leaks than three-piece cans. The two-piece can includes a bottom and side wall formed as one piece and a top, as contrasted to the three-piece can which includes separate top, bottom and side wall components.
Presses for forming cans are well known in the art. In general, a metallic coil strip or sheet is provided in a desired width. Wide width coil sheets offer economical metal use since slitting of the coil at the mill is elminated and process scrap during manufacture of the can is minimized. Oftentimes, the metallic sheet is precoated with lacquers or enamels when used for cans of the shellow draw variety. For cans of the deep draw variety, the metallic sheet is left uncoated since such cans are coated with lacquers or enamels after the can is formed.
In conventional can manufacturing systems, a plurality of work stations are provided and often include the following steps: blanking, cupping, redrawing, trimming the flange/beading, cleaning, coating, curing and testing. The cup is first blanked and drawn from a coated metallic sheet. The cup is then transferred to separate stations and equipment for selected operations. In some conventional systems only coils or sheets of limited widths can be utilized.
It is known in the art to provide a single work station for blanking, drawing and redrawing a can. Other known systems perform blanking, drawing and reverse redrawing in a single station. These multi-use stations, although functional, are difficult to maintain. If a cup or redrawn cup breaks during the forming process, the downtime for cleaning the tooling of fractured cups and metal scraps is difficult and time consuming, thereby reducing efficiencies. The use of wide width coils dictates a multiplicity of multi-use tooling stations wherein breakouts are likely to occur.
Capital equipment requirements in presses can be minimized if a press can accept coils of various widths and if the press can perform more than one operation.
Consequently, a need exists for improvements in presses for forming cans from metallic stock. It is desirable that such presses accept various widths of metallic stock, particularly wide widths. Furthermore, it is desirable that such a press be capable of performing more than one operation during the formation of a can. The multiple-operation press should include work stations which are separate from one another, but which are operable without having to transfer a can to a separate apparatus.